1. Field of the Invention
The present invention relates to instrument delivery systems and, more particularly, to a latching mechanism for instrument delivery systems.
2. Description of the Related Art
Instrument delivery systems are used to deliver instruments to a position where they are used. For example, instrument delivery systems are used in ophthalmologic examinations, where several instruments are used to examine a patient.
FIG. 1 shows a conventional instrument delivery system 10. Conventional instrument delivery system 10 includes a circular table 12, which is rotatable about its central axis and which includes a locking mechanism (not shown) for locking rotation of circular table 12 at 90.degree. increments. Circular table 12 also includes slide trays 14a-14d, which slide between an opened position and a closed position. Slide tray 14a is shown in FIG. 1 in its opened position, while slide trays 14b-14d are shown in their closed positions. Instruments 16a-16d are respectively supported on slide trays 14a-14d. Electrical power outlets (not shown) are provided on each of slide trays 14a-14d to provide power to instruments 16a-16d, if required.
A patient's chair 18 and an operator's chair 20 are positioned on opposite sides of one of slide trays 14a-14d, with circular table 12 locked in one of its 90.degree. interval positions. Typically, the operator seated in chair 20 rotates circular table 12 to a position such as that shown in FIG. 1, where a selected one of slide trays 14a-14d is located between patient's chair 18 and operator's chair 20 and where circular table 12 is locked by the locking mechanism (not shown) in one of its 90.degree. interval positions. Then, the operator pulls the selected one of the slide trays 14a-14d, i.e., slide tray 14a in FIG. 1, into its opened position, and examines the patient seated in chair 18 using instrument 16a. After examination is completed using instrument 16a, the operator pushes slide tray 14a to its closed position, and rotates circular table 12 to another 90.degree. interval position. Consequently, any desired instrument 16a-16d can be delivered to an examination position between patient's chair 18 and operator's chair 20 by rotating circular table 12 to a selected 90.degree. interval position and pulling the selected one of the slide trays 14a-14d to its opened position.
Typically, conventional instrument delivery system 10 includes a latching mechanism (not shown) for latching and unlatching slide trays 14a-14d in their opened and closed positions. For example, one type of conventional instrument delivery system includes a lever-actuated latching mechanism in each of the slide trays 14a-14d. These lever-actuated latching mechanisms are actuated by levers 22a-22d, which are centrally located on the ends of slide trays 14a-14d. The operation of these lever-actuated latching mechanisms is undesirably noisy and unreliable because the operator is often uncertain of the direction in which levers 22a-22d must be pushed for actuation.
Other conventional instrument delivery systems use remotely-actuated latching mechanisms actuated by remote push buttons 24a-24d. However, remote push buttons 24a-24d require a dedicated left or right hand operation. That is, as shown in FIG. 1, in order to unlatch opened slide tray 14a, the operator must be on the side of slide tray 14a where remote push button 24a is located. Consequently, the operator may be in an inconvenient location for actuating remote push button 24a.